Crea un generatore di fatture PDF in .NET

Molto spesso si presenta la necessità di creare una fattura in formato PDF. Di solito il documento che rappresenta la fattura contiene un layout complesso: un'intestazione con un logo e informazioni sull'azienda, informazioni sul venditore e sull'acquirente, una tabella con gli articoli ordinati, un piè di pagina con informazioni aggiuntive.

Il documento PDF è un documento vettoriale, che non dispone della funzionalità per il layout del contenuto. È possibile scrivere codice di programmazione che disegni il markup del documento sulla pagina PDF utilizzando grafica vettoriale, ma il codice sarebbe complesso e il suo sviluppo potrebbe richiedere molto tempo.

Un'attività complessa potrebbe essere semplificata dividendola in 2 parti:
1. Creazione di un modello di documento in un editor di testo.
2. Scrittura del codice di programmazione che riempie il modello con dati dinamici.

Un documento DOCX memorizza il contenuto sotto forma di markup e pertanto può essere utilizzato per creare un modello di fattura di qualsiasi complessità.
Dalla versione 10.1 di VintaSoft Imaging .NET SDK è diventato possibile modificare i documenti DOCX e XLSX esistenti a livello di programmazione.
È possibile utilizzare questa funzionalità per creare un generatore di fatture semplice e facilmente personalizzabile in formato PDF.

Il generatore di fatture dovrebbe contenere due parti principali:

• il modello di fattura in formato di documento DOCX contenente il markup statico della fattura,
• il codice dell'applicazione che inserisce i dati dinamici nel modello di fattura e salva la fattura nel documento PDF.

I vantaggi della creazione di un generatore di fatture basato sul modello di documento DOCX sono:

• la semplicità di modificare il markup statico della fattura, per fare ciò è sufficiente modificare il modello utilizzando MS Word
• la semplicità del codice dell'applicazione, poiché l'applicazione compila solo i dati

Maggiori dettagli sulla modifica dei documenti DOCX a livello di programmazione sono disponibili qui.


È necessario eseguire i seguenti passaggi per creare il generatore di fatture, che genera la fattura in formato di documento PDF:
1. Creare un modello di fattura Invoice_template.docx utilizzando MS Word, che conterrà tutto il markup statico della fattura.
2. Implementare nell'applicazione la compilazione della fattura con dati dinamici utilizzando la classe DocxDocumentEditor.

Ecco il codice che mostra come creare una fattura e salvarla in un documento PDF:

• Modello di fattura: Invoice_template.docx
• Fattura generata: Invoice.pdf

// The project, which uses this code, must have references to the following assemblies:
// - Vintasoft.Imaging
// - Vintasoft.Imaging.Office.OpenXml
// - Vintasoft.Imaging.Pdf
// - Vintasoft.Barcode

/// <summary>
/// Generates invoice, which is based on DOCX document template.
/// </summary>
public static void GenerateInvoiceUsingDocxTemplate()
{
    // create DOCX document editor and use file "Invoice_template.docx" as document template
    using (Vintasoft.Imaging.Office.OpenXml.Editor.DocxDocumentEditor editor =
        new Vintasoft.Imaging.Office.OpenXml.Editor.DocxDocumentEditor("Invoice_template.docx"))
    {
        // generate test invoice data with 30 items
        InvoiceData testData = GetTestData(30);

        // fill invoice data
        FillInvoiceData(editor, testData);

        // save invoice to a DOCX document if necessary
        //editor.Save("Invoice.docx");

        // export invoice to a PDF document
        editor.Export("Invoice_docx.pdf");
    }
}

/// <summary>
/// Fills the invoice data using DOCX document editor.
/// </summary>
/// <param name="documentEditor">The DOCX document editor.</param>
/// <param name="invoiceData">The invoice data.</param>
private static void FillInvoiceData(
    Vintasoft.Imaging.Office.OpenXml.Editor.DocxDocumentEditor documentEditor,
    InvoiceData invoiceData)
{
    // create QR code image 200x200 px
    using (Vintasoft.Imaging.VintasoftImage qrCodeImage = invoiceData.GetBarcodeImage(200))
    {
        // set barcode image to the image element at index 1
        documentEditor.Images[1].SetImage(qrCodeImage);
    }

    // fill the document header
    documentEditor.Body["[company_name]"] = invoiceData.Company.CompanyName;
    documentEditor.Body["[company_address]"] = invoiceData.Company.Address;
    documentEditor.Body["[company_city]"] = invoiceData.Company.City;
    documentEditor.Body["[company_phone]"] = invoiceData.Company.GetPhones();
    documentEditor.Body["[invoice_number]"] = invoiceData.InvoiceNumber;
    documentEditor.Body["[invoice_date]"] = System.DateTime.Now.ToShortDateString();

    // get all tables of document
    Vintasoft.Imaging.Office.OpenXml.Editor.OpenXmlDocumentTable[] tables = documentEditor.Tables;

    // fill the "Customer Information" table
    Vintasoft.Imaging.Office.OpenXml.Editor.OpenXmlDocumentTable customerInformationTable = tables[0];
    SetCompanyInformation(customerInformationTable, "billing", invoiceData.BillingAddress);
    SetCompanyInformation(customerInformationTable, "shipping", invoiceData.ShippingAddress);

    // fill the "Shipping Method" table
    Vintasoft.Imaging.Office.OpenXml.Editor.OpenXmlDocumentTable shippingMethodTable = tables[1];
    shippingMethodTable["[shipping_method]"] = invoiceData.ShippingMethod;

    // fill the "Order Information" table
    Vintasoft.Imaging.Office.OpenXml.Editor.OpenXmlDocumentTable orderInformationTable = tables[2];
    Vintasoft.Imaging.Office.OpenXml.Editor.OpenXmlDocumentTableRow templateRow = orderInformationTable[1];
    int orderItemNumber = 1;
    // for each item in invoice
    foreach (InvoiceItem orderItem in invoiceData.OrderItems)
    {
        // copy template row and insert copy after template row
        Vintasoft.Imaging.Office.OpenXml.Editor.OpenXmlDocumentTableRow currentRow = templateRow;
        templateRow = (Vintasoft.Imaging.Office.OpenXml.Editor.OpenXmlDocumentTableRow)templateRow.InsertCopyAfterSelf();

        // fill data of current row
        currentRow["[p_n]"] = orderItemNumber.ToString();
        currentRow["[p_description]"] = orderItem.Product;
        currentRow["[p_qty]"] = orderItem.Quantity.ToString();
        currentRow["[p_unit_price]"] = invoiceData.GetPriceAsString(orderItem.Price);
        currentRow["[p_price_total]"] = invoiceData.GetPriceAsString(orderItem.TotalPrice);

        orderItemNumber++;
    }
    // remove template row
    templateRow.Remove();

    // fill order information summary fields
    orderInformationTable["[subtotal]"] = invoiceData.GetPriceAsString(invoiceData.Subtotal);
    orderInformationTable["[tax]"] = invoiceData.GetPriceAsString(invoiceData.Tax);
    orderInformationTable["[shipping]"] = invoiceData.GetPriceAsString(invoiceData.Shipping);
    orderInformationTable["[grand_total]"] = invoiceData.GetPriceAsString(invoiceData.GrandTotal);

    // fill the "Notes" table
    Vintasoft.Imaging.Office.OpenXml.Editor.OpenXmlDocumentTable notesTable = tables[3];
    notesTable["[date]"] = System.DateTime.Now.ToShortDateString();
    notesTable["[time]"] = System.DateTime.Now.ToLongTimeString();
}

/// <summary>
/// Sets the company information.
/// </summary>
/// <param name="table">The table.</param>
/// <param name="fieldName">Name of the field.</param>
/// <param name="company">The company.</param>
private static void SetCompanyInformation(
    Vintasoft.Imaging.Office.OpenXml.Editor.OpenXmlDocumentTable table, 
    string fieldName, 
    Company company)
{
    string fieldFormat = string.Format("[{0}_{1}]", fieldName, "{0}");
    table[string.Format(fieldFormat, "company")] = company.CompanyName;
    table[string.Format(fieldFormat, "name")] = company.Name;
    table[string.Format(fieldFormat, "address")] = company.Address;
    table[string.Format(fieldFormat, "phone")] = company.GetPhones();
    table[string.Format(fieldFormat, "city")] = company.City;
}

Il seguente codice crea i dati di prova per il generatore di fatture:

/// <summary>
/// Returns the invoice test data.
/// </summary>
/// <returns>The invoice test data.</returns>
public static InvoiceData GetTestData(int orderItemsCount)
{
    Company vintasoftCompany = new Company();
    vintasoftCompany.CompanyName = "VintaSoft LLC";

    Company billingCompany = new Company();
    billingCompany.CompanyName = "Billing Global Company Inc.";
    billingCompany.Name = "Mr. Q";
    billingCompany.Address = "Address1";
    billingCompany.City = "City1";
    billingCompany.Phones.Add("9876543210");
    billingCompany.Phones.Add("7654321098 (fax)");

    Company shipingCompany = new Company();
    shipingCompany.CompanyName = "Shipping Global Company Inc.";
    shipingCompany.Name = "Mr. Z";
    shipingCompany.Address = "Address2";
    shipingCompany.City = "City2";
    shipingCompany.Phones.Add("1122334455");
    shipingCompany.Phones.Add("5544332211 (fax)");

    InvoiceData data = new InvoiceData();

    System.Random random = new System.Random();
    data.InvoiceNumber = string.Format("{0}-{1}", random.Next(100000, 999999), random.Next(0, 9));

    data.Company = vintasoftCompany;
    data.BillingAddress = billingCompany;
    data.ShippingAddress = shipingCompany;

    InvoiceItem[] availableProducts = new InvoiceItem[] {
        new InvoiceItem("VintaSoft Imaging .NET SDK, Site license for Desktop PCs", 659.95f),
        new InvoiceItem("VintaSoft Annotation .NET Plug-in, Site license for Desktop PCs", 449.95f),
        new InvoiceItem("VintaSoft Office .NET Plug-in, Site license for Desktop PCs", 569.95f),
        new InvoiceItem("VintaSoft PDF .NET Plug-in (Reader+Writer), Site license for Desktop PCs", 1499.95f),
        new InvoiceItem("VintaSoft PDF .NET Plug-in (Reader+Writer+VisualEditor), Site license for Desktop PCs", 2999.95f),
        new InvoiceItem("VintaSoft JBIG2 .NET Plug-in, Site license for Desktop PCs", 1139.95f),
        new InvoiceItem("VintaSoft JPEG2000 .NET Plug-in, Site license for Desktop PCs", 689.95f),
        new InvoiceItem("VintaSoft Document Cleaup .NET Plug-in, Site license for Desktop PCs", 569.95f),
        new InvoiceItem("VintaSoft OCR .NET Plug-in, Site license for Desktop PCs", 509.95f),
        new InvoiceItem("VintaSoft DICOM .NET Plug-in (Codec+MPR), Site license for Desktop PCs", 1199.95f),
        new InvoiceItem("VintaSoft Forms Processing .NET Plug-in, Site license for Desktop PCs", 509.95f),
        new InvoiceItem("VintaSoft Barcode .NET SDK (1D+2D Reader+Writer), Site license for Desktop PCs", 1379.95f),
        new InvoiceItem("VintaSoft Twain .NET SDK, Site license", 539.95f)
    };

    for (int i = 0; i < orderItemsCount; i++)
    {
        int quantity = 1 + random.Next(10);
        int index = random.Next(availableProducts.Length - 1);
        data.OrderItems.Add(new InvoiceItem(availableProducts[index], quantity));
    }

    return data;
}

/// <summary>
/// Represents an information about company.
/// </summary>
public class Company
{

    /// <summary>
    /// The company name.
    /// </summary>
    public string CompanyName;

    /// <summary>
    /// The person name.
    /// </summary>
    public string Name;

    /// <summary>
    /// The company location city.
    /// </summary>
    public string City;

    /// <summary>
    /// The company location adress.
    /// </summary>
    public string Address;

    /// <summary>
    /// The company phone numbers.
    /// </summary>
    public System.Collections.Generic.List<string> Phones = new System.Collections.Generic.List<string>();



    /// <summary>
    /// Returns the phone numbers.
    /// </summary>
    public string GetPhones()
    {
        if (Phones.Count == 1)
            return Phones[0];
        System.Text.StringBuilder result = new System.Text.StringBuilder();
        for (int i = 0; i < Phones.Count - 1; i++)
        {
            result.Append(Phones[i]);
            result.Append(", ");
        }
        result.Append(Phones[Phones.Count - 1]);
        return result.ToString();
    }

}

/// <summary>
/// Represents an invoice order item.
/// </summary>
public class InvoiceItem
{

    /// <summary>
    /// Initializes a new instance of the <see cref="InvoiceItem"/> class.
    /// </summary>
    /// <param name="product">The product name.</param>
    /// <param name="price">The product price.</param>
    public InvoiceItem(string product, float price)
    {
        Product = product;
        Quantity = 1;
        Price = price;
    }

    /// <summary>
    /// Initializes a new instance of the <see cref="InvoiceItem"/> class.
    /// </summary>
    /// <param name="source">The source <see cref="InvoiceItem"/>.</param>
    /// <param name="quantity">The product quantity.</param>
    public InvoiceItem(InvoiceItem source, float quantity)
    {
        Product = source.Product;
        Price = source.Price;
        Quantity = quantity;
    }



    /// <summary>
    /// The product name.
    /// </summary>
    public string Product;

    /// <summary>
    /// The product quantity.
    /// </summary>
    public float Quantity;

    /// <summary>
    /// The product price.
    /// </summary>
    public float Price;



    /// <summary>
    /// Gets the product total price.
    /// </summary>
    public float TotalPrice
    {
        get
        {
            return Price * Quantity;
        }
    }

}

/// <summary>
/// Represents an invoice data.
/// </summary>
public class InvoiceData
{

    /// <summary>
    /// The list of order items.
    /// </summary>
    public System.Collections.Generic.List<InvoiceItem> OrderItems = new System.Collections.Generic.List<InvoiceItem>();

    /// <summary>
    /// The invoice number.
    /// </summary>
    public string InvoiceNumber;

    /// <summary>
    /// The shipping method.
    /// </summary>
    public string ShippingMethod = "Email";

    /// <summary>
    /// The company billing address.
    /// </summary>
    public Company BillingAddress = new Company();

    /// <summary>
    /// The company shipping address.
    /// </summary>
    public Company ShippingAddress = new Company();

    /// <summary>
    /// The object that represents information about the company.
    /// </summary>
    public Company Company = new Company();

    /// <summary>
    /// The currency to be used in the invoice.
    /// </summary>
    public string Currency = "EUR";

    /// <summary>
    /// Gets or sets the tax value.
    /// </summary>
    public float Tax = 0;

    /// <summary>
    /// Gets or sets the shipping price.
    /// </summary>
    public float Shipping = 0;



    /// <summary>
    /// Gets the subtotal value.
    /// </summary>
    public float Subtotal
    {
        get
        {
            float value = 0;
            for (int i = 0; i < OrderItems.Count; i++)
                value += OrderItems[i].TotalPrice;
            return value;
        }
    }


    /// <summary>
    /// Gets the grandtotal value.
    /// </summary>
    public float GrandTotal
    {
        get
        {
            return Subtotal + Shipping + Tax;
        }
    }



    /// <summary>
    /// Returns the price as a string.
    /// </summary>
    /// <param name="price">The price.</param>
    /// <returns>The price in string representation.</returns>
    public string GetPriceAsString(float price)
    {
        return string.Format("{0} {1}", price.ToString("f2", System.Globalization.CultureInfo.InvariantCulture), Currency);
    }

    /// <summary>
    /// Creates the QR code image.
    /// </summary>
    /// <param name="size">The barcode size.</param>
    /// <returns>An instance o f<see cref="Vintasoft.Imaging.VintasoftImage"/> class that contains QR code image.</returns>
    public Vintasoft.Imaging.VintasoftImage GetBarcodeImage(int size)
    {
        Vintasoft.Barcode.BarcodeWriter writer = new Vintasoft.Barcode.BarcodeWriter();

        writer.Settings.Barcode = Vintasoft.Barcode.BarcodeType.QR;

        writer.Settings.Value = string.Format("INVOICE={0};TOTAL={1}", InvoiceNumber, GetPriceAsString(GrandTotal));

        writer.Settings.SetWidth(size);

        Vintasoft.Imaging.VintasoftImage result = 
            new Vintasoft.Imaging.VintasoftImage(writer.GetBarcodeAsBitmap(), true);
        result.Crop(new System.Drawing.Rectangle(0, 0, result.Width, result.Width));

        return result;
    }
}